postscaenium

postscaenĭum or poscaenĭum (-cen-), ii, n. [post-scena],

• the part of the theatre behind the scenes, the postscenium; trop., for secret, mystery: postscenia vitae, those parts of life which are behind the scenes, Lucr. 4, 1186; v. Lachm. ad h. l.